Upon his father's death in 1428, Gerhard became Count of Ravensberg. In 1437, his uncle Adolf died without heirs and Gerhard inherited his title as Duke of Jülich-Berg. Gerhard continued his uncle's fight for the dukedom of Guelders, supported by King Albert II of Germany. In 1444 he won the Battle of Linnich but was unable to prevail in his fight for Guelders and ultimately sold his claim to Burgundy and acquired Blankenheim-Löwenberg and Heinsberg from Guelders. He was increasingly unable to govern his territories after 1461. His spouse Sophie of Saxe-Lauenburg then wielded regency for him.